Submitted to: Forest Service Remote Sensing Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 5/10/2006
Publication Date: 6/15/2006
Citation: Everitt, J.H., Flores, D., Yang, C., Fletcher, R.S., Deloach Jr, C.J., Davis, M.R. 2006. Using remote sensing to assess biological control damage of two invasive plant species. Forest Service Remote Sensing Conference Proceedings. CDROM. Interpretive Summary: The invasion and spread of undesirable plant species in wetlands and riparian zones present serious problems to resource managers. Giant salvinia is an invasive fern that has invaded and clogged waterways in many areas of the world. Saltcedar is an exotic shrub introduced to the United States as an ornamental and for erosion control that has escaped cultivation and invaded many riparian zones in the southwestern U. S. and Mexico. The salvinia weevil has been widely used to control giant salvinia, while the leaf beetle has been used to control saltcedar. Research was conducted to evaluate the potential of using remote sensing technology for assessing control of giant salvinia and saltcedear by the salvinia weevil and leaf beetle, respectively. Field reflectance measurements showed that giant salvinia and saltcedar plants exhibiting feeding damage from these insects had different visible/near-infrared reflectance from healthy plants. Giant salvinia and saltcedar plants with feeding damage could be distinguished on color-infrared and conventional color aerial photographs, respectively. These results should be of interest to resource managers interested in controlling these noxious weeds.
Technical Abstract: A study was conducted to determine the feasibility of using remote sensing technology to assess feeding damage on the aquatic weed, giant salvinia (Salvinia molesta), and the riparian shrub, saltcedar (Tamarix ramosissima), by the salvinia weevil (Cyrtobagous salviniae) and the Chinese leaf beetle (Diorabda elongata), respectively. Field reflectance measurements showed that giant salvinia and saltcedar plants exhibiting feeding damage had significantly different visible and/or near-infrared reflectance than healthy plants. Giant salvinia and saltcedar plants exhibiting feeding damage could be distinguished from healthy plants on color-infrared and conventional color aerial photographs, respectively. These results indicate remotely sensed data has considerable potential for assessing biological control of these two invasive weeds.